Below is a diagram of the different geological eras. This makes it a bit easier to read and understand other parts of the website and the documentation. We are now living in the Holocene, part of the Quaternary epoch. The main classification is the "Era", which is then further subdivided into "Periods". We use the time scale of the International Commission on Stratigraphy. In an international context, this committee determines the upper and lower limits of the various time periods. They use as many absolute time dates of the different layers as possible. A so-called type section is established for each unit where it is best developed.